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Alarm-class torpedo gunboat
|Class before=''Sharpshooter''-class torpedo gunboat |Class after=''Dryad''-class torpedo gunboat |Subclasses= |Built range=1892–1893 |In commission range=1893–1924 |Total ships building= |Total ships planned= |Total ships completed=11 |Total ships cancelled= |Total ships active= |Total ships laid up= |Total ships lost=3 |Total ships retired= |Total ships scrapped=8 |Total ships preserved= }} |module2= |Ship beam= |Ship draught= maximum |Ship power= (except Speedy - 5,000ihp) |Ship propulsion= * Twin 3-cylinder vertical triple-expansion steam engines * Locomotive boilers * Twin screws (except Speedy - water-tube boilers) |Ship speed= |Ship complement= 91 |Ship armament= Jason, Hebe, Circe, Onyx, Leda: * 1 × fixed bow torpedo tube * 2 × revolving 14-inch torpedo tubes * 2 × fixed 14-inch torpedo tubes * 2 × QF guns * 4 × 3-pounder guns * 1 × Gardner machine gun Alarm, Jaseur, Niger, Reynard, Speedy, Antelope: * 1 × fixed bow 18-inch (450mm) torpedo tube * 2 × revolving 18-inch torpedo tubes * 2 × QF guns * 4 × 3-pounder guns * 1 × Gardner machine gun }} }} The Alarm-class torpedo gunboat was the penultimate class of torpedo gunboat built for the Royal Navy. The class was contemporary with the early torpedo boat destroyers, which were faster and better suited to accompanying the battlefleet. By World War I the class had either been sold, converted to submarine depot ships or minesweepers, or reduced to harbour service. Three of the class were lost during World War I while serving in the minesweeping role. Design The Alarm class was designed by Sir William White in 1889 as an enlarged version of his previous ''Sharpshooter'' class. They had a length overall of , a beam of and a displacement of 810 tons. They were engined with two sets of vertical triple-expansion steam engines, two locomotive-type boilers, and twin screws. This layout produced , giving them a speed of with forced draught. They carried between 100 and 160 tons of coal and were manned by 91 sailors and officers. Thornycroft Special - HMS Speedy While officially classed with the Alarm class, the Speedy was actually a separate design. The Naval Defence Act of 1889 authorised the purchase of an Alarm-class torpedo gunboat built to a design by John I. Thornycroft & Company and built in their yard at Chiswick. Speedy was a three-funnelled vessel (compared to the two-funnelled Admiralty design), but the key difference was the use of water-tube boilers instead of locomotive-type boilers; she produced at least and could make . The use of water-tube boilers was a key feature of the new torpedo boat destoyers that would make torpedo gunboats (including the Alarm class) obsolete. Armament At build the class was fitted with two QF /45-pounder guns, four 3-pounder guns and one Gardner machine gun. Five torpedo tubes were fitted in the first five vessels, but this was changed to three 18-inch (450mm) torpedo tubes in the rest of the class. They were arranged as a pair of revolving deck mounts, a pair of fixed deck mounts (deleted in the later vessels) and a single bow-mounted tube; three reloads were provided. Ships See also References * Category:Torpedo gunboat classes Alarm-class torpedo gunboats A